The present invention relates to a surveying apparatus. More particularly, the present invention relates to an improvement in a surveying apparatus in which a laser projector is supported by a gimbal mechanism so as to tilt the laser projector.
In a conventional laser surveying apparatus, such as the laser surveying apparatus disclosed in JP-H06-26861A for example, a perforated concave portion having a hemispherical configuration is formed in the center of a casing 50, and a laser projector 51 which emits a laser beam is tiltably engaged freely and supported by the concave portion.
A head of the laser projector 51 is provided with a prism supporting body 52 which rotates around the center of axle of the laser projector 51. A scan gear is fitted to the prism supporting body 52, so that the prism supporting body 52 is adapted to rotate around the center of axle of the laser projector 51 by a scan motor 53′ through the scan gear. Thus, the prism supporting body 52 and the scan gear structure a rotation section 53.
The prism supporting body 52 is also provided with a pentaprism 54. The pentaprism 54 orthogonally deflects the laser beam emitted from a direction of the center of axle of the laser projector 51 so as to project the laser beam in a horizontal direction.
In a midway part of the laser projector 51 protruded from the concave portion, a fixed bubble tube 55 and a fixed bubble tube 56, structuring an inclination detector for detecting an inclination of the laser projector 51, are provided orthogonally to each other in such a manner as to be perpendicular to the center of axle of the laser projector 51, to detect verticality of the laser projector 51.
A lower end part of the laser projector 51 is provided with a base plate 57 provided tiltably in a direction perpendicular to the laser projector 51. An arbitrary angle setting bubble tube 58 and an arbitrary angle setting bubble tube 59, both adapted to detect the inclination of the laser projector 51, are provided on the base plate 57.
The base plate 57 is tilted by an arbitrary angle setting driving section 60 and an arbitrary angle setting driving section 61. Note that a tilting direction of the base plate 57 and directions to which the arbitrary angle setting bubble tubes 58 and 59 are provided correspond to a tilting direction of the laser projector 51.
Tilting arm 62 and tilting arm 63 for tilting the laser projector 51 are protruded and extended from the laser projector 51 orthogonally in a horizontal direction, respectively. The tilting arms 62 and 63 are engaged with tilt driving sections 64 and 65 through engagement pins, respectively.
Now, leveling for setting the laser projector 51 vertically in accordance with the conventional laser surveying apparatus will be described.
The tilt driving sections 64 and 65 are driven until each of the fixed bubble tubes 55 and 56 detects horizontality based on a result of detection of each of the fixed bubble tubes 55 and 56, so as to compensate the inclination of the laser projector 51. When the fixed bubble tubes 55 and 56 have detected the horizontality, the center of axle of the laser projector 51 is leveled vertically.
Next, inclination setting for freely tilting the laser projector 51 in arbitrary directions in accordance with the conventional laser surveying apparatus will be described. At first, setting of the inclination of the laser projector 51 in an X-direction or a first direction will be explained.
The arbitrary angle setting driving section 60 is actuated to tilt the base plate 57 in the X-direction or the first direction at an arbitrary angle. The arbitrary angle setting driving section 60 is used to set a predetermined angle of inclination of the laser projector 51 based on the number of drive pulses. Then, the tilt driving section 64 is actuated based on a result of detection of the arbitrary angle setting bubble tube 58 until the tilted arbitrary angle setting bubble tube 58, provided in the X-direction, detects the horizontality, so as to tilt the laser projector 51. When the arbitrary angle setting bubble tube 58 has detected the horizontality, the laser projector 51 is set at the predetermined angle of inclination.
Furthermore, the other arbitrary angle setting driving section 61, the arbitrary angle setting bubble tube 59 and the tilt driving section 65, which are perpendicular to the arbitrary angle setting driving section 60, the arbitrary angle setting bubble tube 58 and the tilt driving section 64, respectively, are similarly activated to detect the horizontality in a Y-direction or a second direction. Thereby, the inclination setting of the laser projector 51 in two directions is possible.
However, because the conventional laser surveying apparatus including the laser surveying apparatus disclosed in JP-H06-26861A employs a pivot structure in which the laser projector or a laser projecting section is supported by the hemispherical concave portion, there is a problem that, although it has the reduced play, a wide range of inclination of the laser projector cannot be obtained structurally.
In addition, there has been also known a laser surveying apparatus which employs a structure in which a laser projector is supported by a gimbal mechanism and a tilting mechanism is utilized to tilt the laser projector. In the conventional laser surveying apparatus utilizing the gimbal mechanism, however, it cannot prevent generation of the play in a bearing part of the gimbal mechanism. Therefore, the conventional laser surveying apparatus utilizing the gimbal mechanism is not suitable for the purpose requiring a precise angle of tilt of the laser projector.